Improved Parallel Composition of Labelled Petri Nets

Parallel composition of labelled Petri nets is a fundamental operation in modular design. It is often used to combine models of subsystems into a model of the whole system. Unfortunately, the standard definition of parallel composition almost always yields a ´messy´ Petri net, with many implicit places, causing performance deterioration in tools that are based on structural methods. In this paper we propose an optimised algorithm for computing the parallel composition. It often produces nets with fewer implicit places, which are thus better suited for subsequent application of structural methods.